There are certain milestones that mark the arrival of a fashion designer into the international pantheon of greats, and for Elie Saab, more than 30 years after first launching his label in Beirut, most of those have already been achieved. Royalty as customers? Check. Oscars moment? Check. Acceptance into the Chambre Syndicale de la Haute Couture? Check, check, check shower head china.

So far, so critically acclaimed. However, it’s only those designers with genuine commercial heft that are able to count Saab’s latest accolade among their achievements: the invitation to design a limited-edition Evian bottle might sound like straight commerce, but it’s a very significant indicator of a brand’s elevation. Saab’s launches today, and will be available later this month.

“But is this art?” one hears the fashion purists cry. Perhaps it’s not, but it’s a prestigious brief that the likes of Paul Smith, Issey Miyake and Jean Paul Gaultier were happy to put their names and signature styles to, and a sign of his now immense international profile. Saab has approached it in the same spirit as his predecessors, and it’s informed by his many previous collaborations Roll forming machine.

“For each designer who designed a bottle, we can see clearly his own signature; each one effected properly the essence of the brand,” he says. “So [for me], the execution of the bottle was as complex as I approach my dresses: it appears so simple, but when you go into the technical part, it’s a complicated thing.”

Indeed, to the eye, this is a nice appropriation of lace, but there was considerable thought behind not only the choice of design, which took about four months to finalise, but also the actual production of the bottle, and that seems indicative of the designer’s approach to all his endeavours: no less attention is lavished on a mere water bottle than on a ball gown.

For one thing, the lace was designed specifically for the bottle, rather than being a sample from an existing fabric.

“Evian approached me with the theme of ‘purity’,” says Saab. “We are known for the embroidery, but we are also known as well for the clean-cut, very pure designs. I wanted to respect Evian as well as having my signature on the bottle, so I decided to make the design very transparent, so that you can see through to the purity of the water. Lace is a very noble thing, and the transparency of the lace reflects the transparency of the water.”

After 26 sketches, 17 prototypes were tested in eight colours, the challenge being to create a luxurious version of a fast-moving commodity with a wide reach.

“We had to respect the norms of the product, and to work around the bottle,” he says. “I didn’t even touch the logo, because at the end of the day it is an Evian bottle, not an Elie Saab bottle. And I always try to give each product its own dimension: a dress is a dress, a bottle is a bottle, a perfume is a perfume. Journalists have asked if I designed the bottle as a woman. No. I don’t mix objects together; each thing takes its proper identity.”

As with fashion, designing a two-dimensional object is one thing, but making it work in the round is entirely another, and the custom-made lace design had to be applied using a three-layer relief in which the bottle is turned to create a three-dimensional effect Loop Steamer.

It’s a beautiful thing – and it chimes nicely with the spring/summer 2014 catwalk show that took place on Monday in Paris’s Jardin des Tuileries, a storied collection called “The Lace Garden”.

“It was inspired by nature – an English garden that blossoms more as you go further into the garden,” he explains. “So it starts with fragile colours, like the camellia white, rose Eglantyne, red bougainvillea, verdant green, and then you go further, as if you enter different steps, until you reach the black, which is the night part.”

It was a delicate, ethereal collection, albeit with Saab’s trademark strong, feminine silhouettes, cinched in with belts at the waist; and the architecture of the clothes – from contemporary jumpsuits and tunics to his beloved evening gowns – was made evident with panelled lace and ribbons or bands of solid fabric acting to frame the tailoring.

Frothy tulle and lace was densely ruffled at hems, and tiny silk flowers were appliquéd onto lace foundations, as if scattered by a breeze. A vibrant print sat in the centre or at the edges of dresses, on a white background, and as a metaphorical twilight fell it was gradually obscured by black and silver embroideries and beading.

Though over the seasons his collections have seemed to gain clarity of form and silhouette, gradually shedding any excesses, he insists that the structure is not new.

“I always put the waist, the most feminine part of the woman, as the emphasis, to draw the proper curve of the woman and reflect her silhouette. And I see this structured vision of things, which is maybe from having this passion for architecture and design, not just fashion design. I like straight, clean lines, and for me, when I present dresses in a structured way, I’m showing properly the silhouette of a woman and making her look more feminine and more refined.”

Those pieces will be all over the red carpets come party season, and it’s partly thanks to such heavy exposure that Saab has built on his devoted Middle Eastern following to become a genuinely global brand big enough to attract the likes of Evian.

Helping the name along are his fragrances – currently a small collection of eau de parfum, eau de parfum intense, eau de toilette and body lotion, cream and deodorant, but to be expanded considerably over the next 10 years.

They certainly allow a far wider audience to access the brand, but he’s in no rush to flood the market, preferring to allocate sufficient time and attention to each project. “I like to give each line its proper launch,” he says. “As for make-up, it’s a different world, so we’re more focusing on fragrances for now. It will come, hopefully.”

Saab is not ruling out non-fashion collaborations, though, in the right circumstances. While he turns down far more opportunities than he accepts, he has, in the past, designed yachts and a BMW, and his fascination with interiors and architecture is well known.

“I love design, any kind of design, so I started with fashion, yes – I enjoy it and love fashion a lot – but I am so passionate as well about architecture and design. It’s more than a hobby for me. It’s another line I would really love to pursue.”

And that, perhaps, is why, 30 years on, Saab’s enthusiasm remains undiminished. “It’s passion,” he says. “I’m doing something I love to do. And the more I see appreciation from my clients, the more I have responsibility to do better. I’m an artist as well as an entrepreneur, and I try to mix the artistic side and the business side, and that helps to push further my designs in the most appropriate way.”